The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Apr. 17, 2012
Filed:
Aug. 19, 2009
Yoshio Tomigashi, Osaka, JP;
Yoshio Tomigashi, Osaka, JP;
Sanyo Electric Co., Ltd., , JP;
Abstract
To estimate an initial magnetic pole position, estimated control axes corresponding to the d-axis and q-axis are set as the γ-axis and δ-axis, and a with high frequency rotation voltage or alternating voltage on the γδ coordinate system applied to the motor. A high frequency current iflowing in the motor is then extracted from a detected motor current (armature current) and a direct current component (iγ×iδ)of a product of the γ-axis and δ-axis components of the high frequency current iis derived. Alternatively, the γ'-axis component iγ and the δ′-axis componentof the high frequency current ithat are shifted by π/4 in electric angle from the γ-axis and the δ-axis are used to obtain a direct current component of their product (iγ×iδ). The magnetic pole position is then estimated by computing the axial error Δθ between the γ-d axes utilizing the direct current components.